1. Field of the Invention
The present invention relates to a method of copying data from one storage medium to another storage medium, and more particularly, to a data copying method in which data stored in one storage medium is encrypted and a result of encrypting is recorded on another storage medium via a host, thereby preventing the data from being hacked by unauthorized users and increasing a speed of copying the data.
2. Description of the Related Art
In general, optical discs, which are developed as large capacity storage medias, are classified into a compact disc (CD) that stores music data, a CD-read only memory (CD-ROM) that stores computer data, and digital versatile disk (DVD) that stores video data.
Also, such optical discs can be classified into a read-only type on which data was recorded during disc manufacture and a recordable type which allows a user to record data thereon. Further, the recordable type may be classified into a write once type and a rewritable type. Transfer of data may be made from one disc to another disc or from a hard disk installed in a user's computer to a disc. Such transfer of data is referred to as disk copy.
In general, copyrighted contents is encrypted and a result of encrypting is stored in a storage medium. In detail, such contents are encrypted using a content key and a result of encrypting is stored in a storage medium. The content key is reproduced using a disk drive that reproduces the contents from the storage medium or based on information stored in the storage medium.
FIG. 1 illustrates a conventional method of copying contents stored in a first disc 110 to a second disc 120. Referring to FIG. 1, the first disc 110 stores contents E(K1, Contents) encrypted using a content key K1. When the first disc 110 is loaded into a first drive 112, the first drive 112 reproduces the content key K1 using information stored either in the first disc 110 or the first drive 112.
The information stored in the first disc 110 includes a disc identifier (ID), a random number, and a renewal key block. The disc ID denotes a disc identification number and the renewal key block denotes a set of drive keys that enable identification of unauthorized apparatuses. The information stored in the first drive 112 includes a drive ID, which is a drive identification number, and a device key set. The device key set indicates a set of keys that are provided only to authorized apparatuses for identification of unauthorized apparatuses.
After reproducing the content key K1, the first drive 112 decrypts the contents E(K1, Contents), which has been encrypted and stored in the first disc 110, using the content key K1, thereby obtaining decrypted contents 134. The decrypted contents 134 is sent to a second drive 122 via a host 130.
The second drive 122 reproduces a content key K2 based on information stored in a second disc 120 and information stored in the second drive 122. The information stored in the second disc 120 and the information stored in the second drive 122 are equivalent to that stored in the first disc 110 and that stored in the first drive 112, respectively. Accordingly, a detailed description thereof will be omitted here.
Next, the second drive 122 encrypts the decrypted contents 134 using the content key K2, thereby obtaining encrypted contents E(K2, Contents) 124. The encrypted contents E(K2, Contents) 124 is recorded on the second disc 120.
As described above, the encrypted contents E(K1, Contents) stored in the first disc 110 is decrypted, re-encrypted, and then copied to the second disc 120. A reason for re-encrypting the decrypted content 134 using the content key K2 is to enable a new drive, other than the first and second drives 112 and 122, to reproduce the content key K2 and decrypt the encrypted contents E(K2, Contents) stored in the second disc 120, using the content key K2. In other words, since a content key is reproduced using disc information, the new drive cannot decrypt the encrypted contents E(K2, Contents) stored in the second disc 120 using the previous key K1.
In the conventional data copying method, contents that are not encrypted are, however, transmitted from the first drive 112 to the host 130 and then to the second drive 122, thus guaranteeing security for the contents. For instance, such contents may be intercepted or hacked by unauthorized users who access the host 130.
Further, the conventional data copying method is disadvantageous in that in a considerable amount of time is required in copying contents from one storage medium to another storage medium, since the contents must be encrypted, decrypted, and re-encrypted.